:root {
    --white-color: #ffffff;
    --black-color: #000000;
    --green-color: #259b8f;
    --cyan-color: #42c0f0;
}
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    min-height: 100vh;
    overflow-x: hidden;
    background: linear-gradient(90deg, var(--black-color) 50%, var(--cyan-color) 50%);
    position: relative;
}
/* Transition effect */
body::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, 
        var(--black-color) 49.5%, 
        transparent 50%, 
        var(--cyan-color) 50.5%);
    z-index: -1;
}
/* Main container */
.login-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
}
/* Login card */
.login-card {
    background-color: rgba(255, 255, 255, 0.95);
    border-radius: 5px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.3);
    width: 100%;
    max-width: 450px;
    padding: 40px 35px;
    position: relative;
    overflow: hidden;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}
/* Logo style */
.logo-container {
    text-align: center;
    margin-bottom: 30px;
}
.logo-img img {
    width: 260px;
    height: auto;
}
.logo-text {
    color: #666;
    font-size: .95rem;
    letter-spacing: 2px;
    text-transform: uppercase;
    margin-top: 5px;
}
/* Form field styles */
.form-label {
    font-weight: 600;
    color: #444;
    margin-bottom: 8px;
    font-size: 0.95rem;
}
/* Input group styles */
.input-group:not(.has-validation) > .dropdown-toggle:nth-last-child(n+3), 
.input-group:not(.has-validation) > .form-floating:not(:last-child) > .form-control, 
.input-group:not(.has-validation) > .form-floating:not(:last-child) > .form-select, 
.input-group:not(.has-validation) > :not(:last-child):not(.dropdown-toggle):not(.dropdown-menu):not(.form-floating) {
    border-top-right-radius: var(--bs-border-radius);
    border-bottom-right-radius: var(--bs-border-radius);
}
.input-group {
    margin-bottom: 25px;
}
.input-group-text {
    background-color: #f8f9fa;
    border-right: none;
    color: #42c0f0;
    font-size: 1.1rem;
}
.form-control {
    padding: 12px 15px;
    font-size: 1rem;
    transition: all 0.3s;
}
.form-control:focus {
    box-shadow: 0 0 0 0.10rem rgba(66, 192, 240, 0.25);
    border-color: #86d9ff;
}
/* Button submit styles */
.btn-login {
    background-color: var(--green-color);
    color: var(--white-color);
    border: none;
    padding: 12px;
    font-weight: 600;
    font-size: 1.1rem;
    border-radius: var(--bs-border-radius);
    width: 100%;
    margin-top: 10px;
    transition: all 0.3s;
    letter-spacing: 1px;
}
.btn-login:hover {
    background-color: color-mix(in srgb, var(--green-color), var(--black-color) 20%);
    color: var(--white-color);
}
.btn-login .spinner-border {
    color: var(--white-color) !important;
    --bs-spinner-border-width: 0.15em;
}
.btn-login:disabled {
    background-color: var(--green-color) !important;
    opacity: 0.8;
    color: var(--white-color) !important;
}
/* Responsive */
@media (max-width: 768px) {
    body {
        background: linear-gradient(180deg, var(--cyan-color) 50%, var(--black-color) 50%);
    }
    body::before {
        background: linear-gradient(180deg, 
            var(--cyan-color) 49.5%, 
            transparent 50%, 
            var(--black-color) 50.5%);
    }
    .login-card {
        padding: 30px 25px;
        max-width: 90%;
    }
}
@media (max-width: 576px) {
    .login-card {
        padding: 25px 20px;
    }
    .logo-text {
        font-size: 1.5rem;
    }
}